Properties of the Number 81209

Eighty-One Thousand Two Hundred Nine

Basics

Value: 81208 → 81209 → 81210

Parity: odd

Prime: No

Previous Prime: 81203

Next Prime: 81223

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 17 ² × 281

Divisors: 1, 17, 281, 289, 4777, 81209

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110100111001

Octal: 236471

Duodecimal: 3ABB5

Hexadecimal: 13d39

Square: 6594901681

Square Root: 284.9719284420836

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Expansion of 1/(1 + x * ∑_k>=1 prime(k)*x^k). A307899

a(n) = (10n+1)*(10n+9). A1535

a(n) = determinant([a(n-1), a(n-2); a(n-4), a(n-3)]) for n >= 5, a(n) = n otherwise. A337188

a(n) = ∑_k=0..n (-1)^n-k*n^k. A81209